Fig. 9.4
• A small quantity of water will remain in the
d.h.w. heat exchanger after draining. If the
boiler is being drained to prevent freez-
ing, the d.h.w. heat exchanger must be
removed and inverted to drain fully or an
antifreeze solution added.
9.5
Combustion analysis check
It is recommended that a combustion analy-
sis check is made. Remove the plug as in-
dicated in Fig. 9.1 and carry out combustion
analysis check and adjustment if necessary
as described in the section Gas valve-Ad-
justment of the Service manual.
Reference figures are given in the sections
"Technical Data" on pag. 24 or pag. 26 of
this manual.
9.6
Cleaning the condensing heat
exchanger and burner
To remove the burner-fan group I (Fig. 9.5):
• Take off the front and side panels of the
case.
• Remove the sealed chamber lid.
• Disconnect the connectors of the ignition
electrodes E and detection electrode D
(Fig. 9.5).
- 54 -
MAINTENANCE
F
26
D
F
I
G
H
Fig. 9.5
• Disconnect the rubber pipe J (Fig. 9.6).
• Unscrew the gas connector H (Fig. 9.5).
• Remove the fixing fork K and remove the
gas pipe L (Fig. 9.6).
Fig. 9.6
K
L
F
E
J